The Coase Theorem and
the Two Fundamental Theorems of Welfare Economics
Daniel
Shaviro*
Both the Coase Theorem and the two Fundamental
Theorems of Welfare Economics are well-known.
Less widely recognized, however, is their close intellectual
relationship, which helps us to understand the nature of one of Ronald Coase’s main
contributions.
The First Fundamental Theorem of
Welfare Economics holds that a competitive equilibrium, where supply equals
demand, maximizes social efficiency.[1] The Second Fundamental Theorem of Welfare
Economics holds that society can attain any efficient outcome by suitably
redistributing resources among individuals and allowing them to freely trade.[2]
Two different ways of stating the Coase
Theorem help to make clear its relationship to each of these propositions. First, suppose we state it as follows: “When
there are well-defined property rights and costless bargaining, the
negotiations between the party creating the externality and the party affected
by the externality can bring about the socially optimal market quantity.”[3] This is basically the First Fundamental
Theorem, supplemented by the point that all a market requires is well-defined
property rights that can cheaply be transferred.
Now suppose we state it as follows:
“The efficient solution to an externality does not depend on which party is
assigned the property rights, so long as someone is assigned those rights.”[4] This is basically the Second Fundamental
Theorem, again with the added point that distributable “resources” can include
property rights with respect to the creation of externalities.
The two Fundamental Theorems of Welfare
Economics predate the Coase Theorem by many decades,[5]
and surely were well-known to the “room full of
skeptical Chicago economists – including future Nobel laureates Milton Friedman and George
Stigler”[6]
who debated it with Coase on that famous evening when he first presented his
reasoning. What, then, was actually
novel about the Coase Theorem?
The answer, I believe,
lies in its extending the Welfare Theorems’ range of application. Rather than applying just to readily
observable markets for consumer goods in the field of organized economic production,
they can apply wherever their basic underlying assumptions hold.[7] Coase understood that the right either to
engage in or to block polluting activity could be just like ownership of a
widget. And a “market” could be
understood as any setting where people have well-defined property rights that
they can transfer through low-cost transactions.[8]
Coase was thus a prominent early mover
in one of the major developments of the last fifty-odd years in law and related
social sciences: the steady expansion of the realm of neoclassical economic
reasoning. To be sure, even before Coase, pollution was well-understood to
involve “economic activity” that called for an “economic analysis” of
government policy responses. Later
decades would see economists ranging considerably further out of their
ancestral realm of studying organized economic production. Consider, for example, Gary Becker’s Treatise
on the Family,[9]
applying neoclassical economic reasoning to study of the household, or Richard
Posner’s The Economics of Justice,[10]
taking “an economic approach to issues – including the meaning of justice, the
origin of the state, primitive law, retribution, the right of privacy,
defamation, racial discrimination, and affirmative action – that are not
generally considered economic.”[11] But Coase was an early mover, important not
just for how he advanced the economic analysis of externalities, but also as a
pioneer and harbinger of economic reasoning’s broader future.
*
Wayne Perry Professor of Taxation, NYU Law School.
[2]
Id. at 53.
[3]
Id. at 130.
[4]
Id. at 131.
[5]
They were first set forth by Pareto in 1894.
See John S. Chipman, The Fundamental Theorems of Welfare Economics
(2002), available on-line at http://www.econ.umn.edu/~jchipman/econ4960/ftwe2_all.pdf
.
[6]
Sarah Galer, Ronald Coase Still Stirs Debate at 101 (2012), available on-line
at http://www.uchicago.edu/features/20120423_coase/.
[7]
For example, “[t]o establish the First Theorem, we need to sketch a general
equilibrium model of an economy. Assume
all individuals are price takers: none is big enough, or motivated enough, to
act like a monopolist. Assume each
individual chooses his consumption bundle to maximize his utility, subject to
his budget constraint. Assume each firm
chooses its production vector, or input-output vector, to maximize its profits
subject to some production constraint.
Note the presumption of [rationally pursued] self-interest. An individual cares only about his own
utility, which depends on his own consumption.
A firm cares only about its profits.”
Allan M. Feldman, Welfare Economics, in John Eatwell, Murray Milgate,
and Peter Newman (eds.), The New Palgrave
Dictionary of Economics, 4: 889 (1987).
[8]
Coase’s notion of transaction cost can be viewed as underlying the existence of
a well-functioning market.
[11]
Id. at 1.
Coase’s work, among many other things, establishes a fundamental challenge to anyone working in my field of corporate reorganizations, the law dedicated to preserving financially distressed firms. Coase’s insight into the nature of the firm puts a natural limit on how much value a law of corporate reorganizations can bring. To make the case that a business has substantial value as a going concern and is worth saving, one must establish both that the business’s relationships are costly to replicate and that the business is itself sound.
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